We use one of these - http://www.ebay.co.uk/itm/DC-12V-24V.../291087849273?

The 12V 100W version for £7.99 is fine for a single Accucel 6. We actually have a 400W unit that drives 4 of the new 80W Accucels so we can fast charge all out batteries at an event.

Be aware, XBox PSU's output 12V and 5V Supplies.